feat: 领券数据看板 — coupon_session 流水表 + admin 聚合接口

- 新表 coupon_session(一次领券一行,trace_id 唯一):POST /api/v1/coupon/session
  两段 upsert(发起 started / 收尾 completed·failed·abandoned),记全程耗时、各平台耗时、
  机型/ROM、app_env、trace_url、origin_package(发起来源)。
- admin GET /admin/api/coupon-data:发起/完成数 + 平均耗时 + P5/P50/P95/P99(Python 算分位,
  SQLite 无 percentile)+ 按天/小时趋势 + 明细分页 + join 用户手机号/昵称,app_env 默认 prod;
  另加 GET /admin/api/coupon-data/user-records 供「点手机号看该用户全部领券」抽屉。
- 迁移拆 3 个:建表 coupon_session_table + trace_url 加列 + origin_package 加列
  (建表迁移已被某环境应用后改它不重跑,故新列单独加列迁移)。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

app/admin/main.py

@@ -21,6 +21,7 @@ from app.admin.routers.audit import router as audit_router
 from app.admin.routers.auth import router as auth_router
 from app.admin.routers.comparison import router as comparison_router
 from app.admin.routers.config import router as config_router
+from app.admin.routers.coupon_data import router as coupon_data_router
 from app.admin.routers.cps import router as cps_router
 from app.admin.routers.dashboard import router as dashboard_router
 from app.admin.routers.device_liveness import router as device_liveness_router
@@ -101,6 +102,7 @@ admin_app.include_router(audit_router)
 admin_app.include_router(config_router)
 admin_app.include_router(comparison_router)
 admin_app.include_router(cps_router)
+admin_app.include_router(coupon_data_router)
 admin_app.include_router(ad_audit_router)
 admin_app.include_router(ad_config_router)
 admin_app.include_router(ad_revenue_router)